An electronic camera with interchangeable lenses is known. In this kind of the electronic camera, various lens units (interchangeable lenses) are interchanged to perform desired shooting. The electronic camera with the interchangeable lenses is composed of the lens unit and a camera body. In general, an imaging device for taking a subject image is disposed in the camera body.
However, when the imaging device is disposed in the camera body, it is necessary to optically connect a lens group of the lens unit to the imaging device of the camera body. Thus, technical knowledge is sometimes required and there arises a problem in that handling is difficult for beginners.
In consideration of this, it is proposed to dispose the imaging device in the lens unit of the lens-interchangeable electronic camera. Such a kind of the electronic camera has an advantage that handling is simplified. Moreover, there is another advantage that dust or the like is prevented from adhering to the imaging device, since it is possible to seal up the lens unit in a state that the imaging device is built therein.
By the way, as to an attachment way for attaching the lens unit to the camera body, various ways are known. Some of the attachment ways adopt a bayonet style, and some of them utilize a magnet.
Japanese Patent Laid-Open Publication No. 8-227096 teaches a camera in which a lens unit is attached by using magnets. In this camera, a mounting plate of the camera body is provided with the magnets, and a rear surface of the lens unit is provided with magnetic members to be attracted by the magnets which are disposed along the periphery of the mounting plate. All center angles, each of which is formed between any two magnets, are adapted to be different to each other. Meanwhile, the magnetic members are disposed so as to keep a mirror image relation relative to the magnets. After pressing the rear surface of the lens unit against the mounting plate of the camera body, the lens unit is rotated so that the lens unit is set to a predetermined attachment position of the camera body.
Japanese Patent Laid-Open Publication No. 2000-50138 teaches an electronic camera in which a lens unit is attached via a connection plate. This electronic camera is of a type that an imaging device is disposed in a lens unit. In this electronic camera, the lens unit is provided with an engagement claw and a camera body is provided with the connection plate having an engagement portion with which the engagement claw engages. After pressing the lens unit against the camera body via the connection plate, the lens unit is slid to engage the engagement claw with the engagement portion so that the lens unit is set to a predetermined attachment position of the camera body.
As to the lens-interchangeable electronic camera of the type that the imaging device is disposed in the lens unit, it is unnecessary to exclusively attach the lens unit to the predetermined attachment position of the camera body. Thus, it is preferable to use an attachment way which is more appropriate in comparison with a conventional attachment way such as described in the above-noted Publications.
In the coming years, the lens unit will become small, lightweight and inexpensive with the rise of technology, and various lens units will be provided. Thus, it is especially desired to obtain a structure in which the lens unit can be easily attached and detached.